The present invention relates generally to a magnetic head slider that flies with a fine clearance above a traveling recording medium or comes into intermittent contact with the traveling recording medium, a magnetic head assembly incorporating the magnetic head slider therein, and a magnetic disk drive. More specifically, the present invention relates to a magnetic head slider suitable for a magnetic disk drive in which a small-diameter disk having a diameter of 45.7 mm (1.8 in.) or less is used.
A magnetic head slider is supported by a flexure attached to a suspension. The magnetic head slider flies with a fine clearance above a magnetic disk or comes into intermittent contact with the magnetic disk so as to write or read data thereon or therefrom. Patent Document 1 (Japanese Patent Laid-open No. 2003-123422) discloses a negative pressure slider which is widely used at present. FIG. 13 shows the construction of the negative pressure slider. A medium opposing surface (i.e., a bearing surface) 108 of a slider 101 includes an air bearing surface 102 (102a, 102b and 102c), a shallowly grooved surface 104 (104a, 104b and 104c) having a step slightly deeper than the air bearing surface 102, and a deeply grooved surface 105 which is more deeply grooved than the shallowly grooved surface 104. The air bearing surface 102 includes a pair of right and left inflow side air bearing surfaces 102a and 102b, which are disposed on an air inflow side rearward of the shallowly grooved surface 104, and a center pad 102c, which is provided at an air outflow end, for mounting a magnetic head 103 thereon. The shallowly grooved surface 104 includes a shallowly grooved surface 104a on the air inflow side, shallowly grooved rails 104b on both sides of the shallowly grooved surface 104a, and a center pad shallowly grooved surface 104c disposed on the air outflow side of the center pad 102c. The deeply grooved surface 105 is substantially surrounded by the shallowly grooved surface 104a disposed on the air inflow side, the inflow side air bearing surfaces 102a and 102b, and the shallowly grooved rails 104b disposed on both sides. According to this construction, the shallowly grooved surface 104 and the air bearing surface 102 provide a step air bearing function. This step air bearing function generates a lifting force for causing the slider to fly above the magnetic disk. At the same time, the function produces a negative pressure at the deeply grooved surface 105. An appropriate air bearing stiffness is thus ensured to allow the slider to stably fly. The slider has a length Lx of 1.25 mm, a width Ly of 1.0 mm, and a height Lz of 0.3 mm. As a result, the ratio Lx/Ly of the slider length to the slider width is 1.25.
A recent trend in the magnetic disk drive is shifted toward a compact magnetic disk drive using a small-diameter disk, to thus meet the need for a high recording density and aim at application to compact digital equipment. This trend raises a problem of a decrease in effective data area on a disk. As an approach to solving this problem, there is known a method for reducing the slider in size. There has been developed a compact slider representing reduction in dimension of about 70% of the above-described slider which is widely used at present. FIG. 14 is a plan view showing a compact slider. A slider has a length Lx of 0.85 mm, a width Ly of 0.7 mm, and a height Lz of 0.23 mm. The ratio Lx/Ly of the slider length to the slider width is 1.21. A shallowly grooved surface 109 having a width of 30 μm is formed at a side end of each of air bearing surfaces 102a and 102b on an inflow side, and further, a cutting margin 110 having a width of 30 μm, which is equal to the depth of a deeply grooved surface 105, is formed outside of the shallowly grooved surface 109. As a consequence, a length L2 between the end of the air bearing surface and the end of the slider becomes 60 μm, and further, a length L1 between the end of the air bearing surface and the shallowly grooved surface becomes 30 μm. A suspension load to be applied to a slider 101 is positioned at the center of the slider 101. In this manner, the effective data area of the disk becomes wider by 0.3 mm. This signifies a remarkable improvement for a compact magnetic disk drive, in which a disk size is 25.4 mm (1 in.) or 20.3 mm (0.8 in.)
A reduction in size of the slider, or in particular, a reduction in slider width and slider height can be about double the number of sliders which are taken from a wafer having the same size by using a single magnetic head fabricating apparatus. This also yields a benefit of cost reduction of the slider.